Network:Modified create interface to return the D-Bus object ID

Currently, the create interface doesn't return the Object identifier,
this commit is to modify Create Inferface to return the object identifier.

Change-Id: Icbd30481a1173a0c2b8dbe32ba913504555a119a
Signed-off-by: raviteja-b <raviteja28031990@gmail.com>
diff --git a/ethernet_interface.hpp b/ethernet_interface.hpp
index bfe1d54..7d7447d 100644
--- a/ethernet_interface.hpp
+++ b/ethernet_interface.hpp
@@ -31,6 +31,7 @@
     sdbusplus::xyz::openbmc_project::Network::server::MACAddress;
 
 using ServerList = std::vector<std::string>;
+using ObjectPath = sdbusplus::message::object_path;
 
 namespace fs = std::experimental::filesystem;
 
@@ -86,8 +87,8 @@
      *  @param[in] gateway - Gateway ip address.
      */
 
-    void iP(IP::Protocol addressType, std::string ipaddress,
-            uint8_t prefixLength, std::string gateway) override;
+    ObjectPath iP(IP::Protocol addressType, std::string ipaddress,
+                  uint8_t prefixLength, std::string gateway) override;
 
     /* @brief delete the dbus object of the given ipaddress.
      * @param[in] ipaddress - IP address.